Embodiments of methods, apparatus, and systems for extracting impedance for a circuit design are disclosed herein. Some of the disclosed embodiments are computationally efficient and can accurately compute the frequency-dependent impedance of VLSI interconnects and/or intentional inductors in the presence of multi-layer conductive substrates. In certain embodiments, the resulting accuracy and CPU time reduction are a result of a Green's function approach with the correct quasi-static limit, a modified discrete complex image approximation to the Green's function, and a continuous dipole expansion to evaluate the magnetic vector potential at the distances relevant to VLSI interconnects and intentional inductors.
Legal claims defining the scope of protection, as filed with the USPTO.
1. One or more computer-readable memory or storage devices storing computer-executable instructions which when executed by a computer cause the computer to perform a method, the method comprising: receiving layout information indicative of at least signal-wire segments in a circuit design and substrate profile information indicative of electrical characteristics of a substrate over which the circuit design is to be implemented; performing impedance extraction using the layout information and the substrate profile information, wherein the impedance extraction generates a plurality of impedance values for the signal-wire segments and wherein the substrate is not represented by a plurality of filaments during the impedance extraction; and generating a representation of electrical characteristics of the circuit design, the representation comprising the impedance values.
2. The one or more computer-readable memory or storage devices of claim 1 , wherein the impedance extraction is performed using an approximation of a Green's function in the presence of the substrate.
3. The one or more computer-readable memory or storage devices of claim 2 , wherein the Green's function is due to a magnetic dipole.
4. The one or more computer-readable memory or storage devices of claim 1 , wherein the impedance extraction is performed using a representation of the substrate comprising a superposition of complex exponentials.
5. The one or more computer-readable memory or storage devices of claim 1 , wherein the substrate is a multi-layer substrate.
6. The one or more computer-readable memory or storage devices of claim 1 , wherein the representation of the electrical characteristics of the circuit design is a netlist that includes the impedance values.
7. A computer-implemented method, comprising: by computing hardware, receiving layout information indicative of at least signal-wire segments in a circuit design and substrate profile information indicative of electrical characteristics of a substrate over which the circuit design is to be implemented; by the computing hardware, performing impedance extraction using the layout information and the substrate profile information, wherein the impedance extraction generates a plurality of impedance values for the signal-wire segments and wherein the substrate is not represented by a plurality of filaments during the impedance extraction; and by the computing hardware, generating a representation of electrical characteristics of the circuit design, the representation comprising the impedance values.
8. The method of claim 7 , wherein the impedance extraction is performed using an approximation of a Green's function in the presence of the substrate.
9. The method of claim 8 , wherein the Green's function is due to a magnetic dipole.
10. The method of claim 7 , wherein the impedance extraction is performed using a representation of the substrate comprising a superposition of complex exponentials.
11. The method of claim 7 , wherein the substrate is a multi-layer substrate.
12. The method of claim 7 , wherein the representation of the electrical characteristics of the circuit design is a netlist that includes the impedance values.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
December 8, 2014
January 5, 2016
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